SUMMARY The goal of complete malaria elimination from the entire Greater Mekong Subregion (GMS) by 2030 encounters several technical challenges, among which is the increasing prevalence and resilience of Plasmodium vivax to control measures. Mass drug administration has been a critical tool for consideration in the final phase of malaria elimination. In areas where P. vivax prevails, it is important to include mass delivery of primaquine to rid of hypnozoites in the liver. Although mass primaquine preventive treatment (MPPT) has been successfully carried out to reduce and eliminate temperate zone P. vivax, it has not been evaluated in tropical countries. With the planning of implementation of the MPPT strategy by the national malaria control programs in Thailand and Myanmar, the preparedness of the stakeholders from top governmental level to the community level needs to be critically assessed. Therefore, this project aims to 1) assess the acceptability and feasibility of conducting MPPT in malaria endemic villages, 2) assess the readiness and ability of existing healthcare facilities to detect and act on new malaria cases in endemic communities considering elimination, and 3) assess the acceptability and feasibility of implementing enhanced vector-control interventions in endemic communities considering elimination. This research will provide an evidence base regarding MDA with primaquine and will aid in designing and guidelines for the scale up of MPPT in Thailand and Myanmar in order to reach the goal of elimination.